The basic operation and structure of land mobile radio frequency communication systems is known. Land mobile radio communication systems typically comprise one or more radio communication units and one or more repeaters that transceive information via communication resources, also referred to as communication channels, include time slots, frequency pairs and so forth. These communication resources typically reside on narrow spaced channels of various bandwidths, such as 12.5 kHz, 25 kHz, and 30 kHz. Further, these narrow spaced channels are often variously licensed to multiple systems or services within an allocated band. Finally, these bands are often allocated for common narrow-bandwidth channel characteristics which differ with adjacent bands.
Thus, a diverse collection of systems typically simultaneously provide land mobile communications to a common, or overlapping, coverage area. Each system may typically be characterized by different channel characteristics, coverage, and services. Paging and cellular telephony are but two examples of different services provided by different systems with different channel characteristics and system designs.
There is little integration of different systems today. Users typically employ separate distinct radio units for each system, regardless of how close the operating channels are in frequency, which in some cases may even be overlapping. The user further employs a separate and distinct authorization procedure for each system which may vary anywhere from over-the-air transmission, to a land-based telephone call. Also, some services which are one-way only in nature, such as paging, make over-the-air registration impossible.
Due to the necessity for two-way communications, over the air registration is not possible for many radio services. The need for new registration when roaming becomes an inconvenience for many services that require the user to find an alternative communication service to perform a manual registration.
Roaming further presents a plethora of registration and authorization difficulties in that the time duration of roaming service is indeterminate, typically requiring the user to manually invoke a roaming service request each day.
As service theft increases, security of authorization remains a major concern to all communication systems operators and owners. Typical methods of protection involve encryption and authentication of identity codes. Nevertheless, theft of identity and authentication codes can defeat this. Because of the ability of unauthorized users to receive and duplicate codes, encryption becomes necessary to combat the theft of authentication and identity codes that are transmitted over the air. As in almost any security system, the only recourse available to combat an authentication and identity code that has been stolen is to change the codes. Changing codes over-the-air is also known in the art, although such changing procedures are accompanied by ever-increasing complexity to overcome the abilities of the thief to eavesdrop and use codes in an unauthorized manner.
Additionally, reprogramming of communication units on a communication system today is not practical for a variety of technical reasons. Many individual communication systems, such as paging, lack sufficient bandwidth to provide downloading of new programming data without significantly disrupting the prime communication service, i.e., paging. While usage of many or most communication services wanes at night, requiring all communication units to remain active continuously (24 hours) would significantly impact operating characteristics, such as battery life.
Accordingly, there is a need for an simplified method of registration, authorization, and reprogramming for multiple communication services such that automatic over-the-air registration can be performed, as well as over-the-air reprogramming of identity and authorization codes, without impacting unit battery life.